Updated on with 0 views and 0 comments

You are given two non-empty linked lists representing two non-negative integers. The digits are stored in reverse order and each of their nodes contain a single digit. Add the two numbers and return it as a linked list.

You may assume the two numbers do not contain any leading zero, except the number 0 itself.

Example:

Input: (2 -> 4 -> 3) + (5 -> 6 -> 4)
Output: 7 -> 0 -> 8
Explanation: 342 + 465 = 807.

java：

``````/**

* public class ListNode {
*     int val;
*     ListNode next;
*     ListNode(int x) { val = x; }
* }
*/
class Solution {
public ListNode addTwoNumbers(ListNode l1, ListNode l2) {
ListNode dummy = new ListNode(0);
ListNode curr = dummy;
int sum = 0;
while (l1 != null || l2 != null) {
if (l1 != null) {
sum += l1.val;
l1 = l1.next;
}

if (l2 != null) {
sum += l2.val;
l2 = l2.next;
}

curr.next = new ListNode(sum % 10);
sum /= 10;
curr = curr.next;
}

if (sum == 1) {
curr.next = new ListNode(1);
}

return dummy.next;
}
}
``````

go：

``````/**

* type ListNode struct {
*     Val int
*     Next *ListNode
* }
*/
func addTwoNumbers(l1 *ListNode, l2 *ListNode) *ListNode {
var dummy = &ListNode{Val:-1};
var p = dummy

var sum int
for l1 != nil || l2 != nil {
if l1 != nil {
sum += l1.Val
l1 = l1.Next
}
if l2 != nil {
sum += l2.Val
l2 = l2.Next
}

p.Next = &ListNode{Val:sum % 10}
p = p.Next
sum /= 10
}

if sum == 1 {
p.Next = &ListNode{Val:sum}
}

return dummy.Next
}
``````